DhcpEnumSubnets function (dhcpsapi.h)

The DhcpEnumSubnets function returns an enumerated list of subnets defined on the DHCP server.

Syntax

DWORD DHCP_API_FUNCTION DhcpEnumSubnets(
  [in]      DHCP_CONST WCHAR   *ServerIpAddress,
  [in, out] DHCP_RESUME_HANDLE *ResumeHandle,
  [in]      DWORD              PreferredMaximum,
  [out]     LPDHCP_IP_ARRAY    *EnumInfo,
  [out]     DWORD              *ElementsRead,
  [out]     DWORD              *ElementsTotal
);

Parameters

[in] ServerIpAddress

Unicode string that specifies the IP address or hostname of the DHCP server.

[in, out] ResumeHandle

Pointer to a DHCP_RESUME_HANDLE value that identifies the enumeration operation. Initially, this value should be zero, with a successful call returning the handle value used for subsequent enumeration requests. For example, if PreferredMaximum is set to 100, and 200 subnet addresses are stored on the server, the resume handle can be used after the first 100 subnets are retrieved to obtain the next 100 on a subsequent call, and so forth.

[in] PreferredMaximum

Specifies the preferred maximum number of subnet addresses to return. If the number of remaining unenumerated options is less than this value, then that amount will be returned.

[out] EnumInfo

Pointer to a DHCP_IP_ARRAY structure that contains the subnet IDs available on the DHCP server. If no subnets are defined, this value will be null.

[out] ElementsRead

Pointer to a DWORD value that specifies the number of subnet addresses returned in EnumInfo.

[out] ElementsTotal

Pointer to a DWORD value that specifies the number of subnets defined on the DHCP server that have not yet been enumerated.

Return value

This function returns ERROR_SUCCESS upon a successful call. If a call is made with the same ResumeHandle value and all items on the server have been enumerated, this method returns ERROR_NO_MORE_ITEMS with ElementsRead and ElementsTotal set to 0. Otherwise, it returns one of the DHCP Server Management API Error Codes.

Remarks

When no longer needed, the resources consumed for the enumerated data, and all pointers contained within, should be released with DhcpRpcFreeMemory.

This function requires host byte ordering for all DHCP_IP_ADDRESS values in parameter structures.

Requirements

See also

DHCP_IP_ARRAY